Weighing scale



June 10, 1930. T s cH N 1,762,204

WEIGHING SCALE Filed March 29, 1929 3 Sheets-Sheet l FIG; I.

June 10, 1930.

T. H. STRACHAN WEIGHING SCALE Filed March 29, 1929 5 Sheets-Sheet 2 June1930' T. H. STRACHAN wmenme SCALE Filed March 29, 1929 3 Sheets-She t 5Patented June 10, 1930 UNITED STATES PATENT OFFICE 'I'HOMLAS H.STRACHAN, OF LYNBROOK, NEW YORK, ASSIGNOR T DAYTON SCALE GOM- PANY, OFDAYTON, OHIO, A CORPORATION OF NEW JERSEY WEIGHING SCALE Applicationfiled March 29, 1929. Serial No. 850,948.

The present invention relates to indicating devices for scales. Suchdevices may comprise a drum chart having weight and price indicationsthereon and supported by a plurality of spiders mounted on a shaftforming the axis of rotation for said' drum.

The shaft cooperates with the weighing beam and is rotated in proportionto the load offsetting force applied when weighing an article and theindications serve to ascertain the weight and price of the articleweighed.

The operating connections'include a pinion on each end of the drum shaftto cooperate with racks operated from the weighing beam. It is usual topermanently fix the pinions on the shaft by a pressing, shrinking, orthe like process. This is necessary to absolutely prevent shifting ofthe pinion relative to the drum which would destroy the accuracy of theScale. Attached to the pinions on the drum shaft are the end spiderscarrying the drum. Obviously, it is required to rigidly connect thepinions and the end spiders in order to insure accurate wei hing. 95 Inthe prior practice, t e end spider and pinion were not removableseparately from the drum shaft. Consequently, when any of these spidersor the drum chart itself was damaged, the entire drum, pinions, spiders,and chart had to be removed and replaced.

The object of the instant invention is to provide means for rigidlysecuring the spiders to the pinion in such a manner that any or both ofthe end spidersmay be removed while leaving the pinions undisturbed onthe drum shaft.

Furthermore, it has been necessary in the prior art to first fix thepinions and spiders in place on the drum shaft and then carefully lacethe drum chart on the spiders; The fit between the spiders and the chartmust be very snug to provide a smooth unruflied chart after the latteris glued to the spiders. Further, in certain States, the law requiresthat the surface ofthe chart from the reading wire must never exceed avery small fraction of an inch. If the fit of the chart on the spidersisnot sung, the chart will sag and the distance between the chart surfaceand index will exceed the limitsprovidedby' law. The

difliculty of placing a chart with a snug fit on spiders alreadyassembled on the shaft will be obvious and often is the cause of chartsbeing ruflied or spoilt in assembling.

Another object of the invention is therefore to provide a new method ofassembling a chart and spiders in a drum scale which would obviatedamaging of the chart by wrinkling, shrinking, or the like.

Other objects and advantages of this invention will be apparent from thespecification and accompanying drawings which show one embodiment ofthis invention wherein similar reference numerals indicate similar partsand wherein the drawings;

Fig. 1 is a longitudinal sectional view of the drum indicator assembled.

Fig. 2 is a section illustrating the details of the fastening device andmethod of assemblingthe drum and chart.

Fig. 3 is an end view of the drum indicator with certain parts brokenaway.

Fig. 4 is a sectional View on line 4-4 of Fig. 3.

Fig. 5 illustrates the essential details in the spider construction.

Referring to Fig. 1 a shaft 6 'isprovided with two pinions 7 and 8 fixedthereon'at each end and an adjustable flange member 9 fixed to saidshaft by means of set screw 10. Integral with the pinions 7 and 8 areflanges 11 and 12 provided with threaded holes to receive the screws 13and 14. In likemanner the flange member 9 is provided with holes toreceive the screws 15. Washers 16, 17 and 18 are provided with holescorresponding to the holes of the flange members 11, 12and 9 with whichthey respectively cooperate so that by inserting spiders 20, 21 and 22between the flange members and their respective washers and tighteningup onthe holding screws, these spiders will be firmly held in positionon the shaft 6-to form a supporting structure for a chart 23. The spider22 is provided with a flat and comparatively narrow flange 24 around itsperiphery which serves as a central support for'the chart 23. Thespiders 20 and 21 are provided with comparatively wide peripheralflanges 25 and 26 and rolled-over edges 27' and 28 under which edges theend of the chart is inserted to hold it in position and close to theperiphery of said spiders. These spiders are provided with adjustablecounter balance weights 29 which may be moved radially along slottedspokes in the spiders to properly balance them in all directions aboutthe axis. its this construction is old and has no part in the presentinvention, furtl er explanation of this will be unnecessary.

The spider 22 forming the central supporting structure is porvided withholes corresponding to the screw holes in the flange member 9 and isprovided with a center hole of approximately the same diameter of theshaft 6 to receive said shaft and is held rigidly in its centralposition by means of screws and washer 18 to the flange member 9 by thescrews 15.

The two end spiders and 21 are identical in construction and areprovided at the center with a hole 30 which conforms to the contour ofthe pinions 7 and 8 and the flange members 11 and 12 which are cut awayas shown in Fig. 5. Cooperating with the flange members 11 and 12 arewashers 31 provided with a slot running from the periphery through thecenter and near to the periphery on the opposite side. This washer is ofan outside diameter exceeding that of the flange members 11 and 12 andexceeding the hole in the center of the spiders 20 and 21. Thus with thewashers 31 placed to straddle the shaft 6 and the screws 13 and 1d andbearing against the flange members 11 and 12 on one side and the spiders20 and 21 on the other, drawhig down of washers 16 and 17 by screws 13and let will serve to clamp said spiders in position.

The method of assembling the chart and the support therefor is asfollows: The flanged hub 9, intermediate spider 22, washers 16, 17 and18, and pinions 7 and 8 are assembled on shaft 6. The pinions are thenpermanent-1y fastened to the shaft by a pressing operation or the like.Flange 9 is then set in position by means of set screw 10. One of theend spiders is then assembled and fixed to the associated pinion. Asshown in Fig. 2, spider 20 is in assembled condition. The chart 23 isthen placed over the periphery 25 of spider 20 and beneath the flange 27and the latter pressed down to rigidly fix the chart relative to theshaft. The movement of the chart 23 over periphery 25 is not hindered byspider 22 which is in the inclined and unfastened position shown in Fig.2. Spider 22 may now be fixed to the flange 9 by screws threaded intoflange 9 and the washer 18. In being fixed to the shaft at this time,spider 22 will maintain the chart surface taut. The spider 21 is nowmoved between washer 17 and flange 12, the opening 30 in the spider hubbeing large enough to freely pass over the pinion and its flange. Washer31 is then placed between the hub of the spider and the flange 12 thuspreventing movement of the spider past the flange 12. The screws arethen inserted in the washer 17 and flange 12 and the spider 21 clampedtightly in position. The flange 28 of spider 21 is then pressed down onthe chart surface.

If either end spider is damaged, the screws may be removed from theflanges 12 or 13 and respective cooperating washers 17 and 16, theU-shaped washer 31 then removed, and the spider freely moved past thepinion.

WVhile there has been shown and described and pointed out thefundamental novel features of the invention as applied to a singlemodification it will be understood that various omissions andsubstitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in the artwithout departing from the spirit of the invention. It is the intentiontherefore to be limited only as indicated by the scope of the followingclaims:

1. In a weighing scale, an indicator druin comprising a shaft, a pinionrigidly fixed to an end of the shaft, a spider having a hub providedwith an opening permitting the spider to be freely moved axially overand past the pinion, means for rigidly fastening the spider to thepinion, and a chart supported on the periphery of the spider.

2. In a weighing scale, an indicator drum comprising a shaft, a pinionrigidly fixed to an end of the shaft and having a flange at one end, aspider having a hub provided with an opening permitting the spider to befreely moved axially over and past the pinion and flange, a washer openat one end to permit it to be freely placed on the shaft by moving it ina radial direction, the opening in said washer being too small to allowmovement of the washer axially past the pinion and flange, a secondwasher positioned on the shaft, means for clamping the spider to thesecond washer and the pinion flange with the firstnained washer locatedbetween the pinion flange and the spider, and a chart adapted to besupported on the periphery of the spider.

3. A scale drum comprising a shaft, a pair of pinions thereon one ateach end, a cylindrical spider fastened to each pinion, a cylindricalchart adapted to fit over the periphery of the spiders, and a flangeprovided at the outer side of each spider and adapted to be pressed downon the chart to secure it rigidly to the spiders.

l. The method of constructing a drum scale indicator which has acylindrical chart and a supporting structure therefor including a pinionand spider at each end of a shaft, which consists in first rigidlyattaching the piiiions to the shaft, then fixing a s ider to one end ofthe shaft, then inserting t e chart over the attached spider and fixingit thereto, and subsequently inserting the other end spider into thechart, moving it past the associated pinion and fixing it to saidpinion.

5. The method of constructing a drum scale indicator which has acylindrical chart and a supporting structure therefor comprising apinion and spider at each end and an intermediate spider, which consistsin first placing an intermediate spider loosely on the shaft, fixing thepinions permanentl on each end of the shaft, and then rigidly xing oneend spider to associated end pinion, placing the cylindrical chart overthe latter end spider and fixin it thereto, then fixing the intermediatespider to the shaft, and finally moving the remaining end spider pastthe associated end pinion and under the adjacent end of the chart andfixin the chart thereto.

In testimony whereof Iiereto aflix my signature.

THOMAS H. STRAOHAN.

